|Coq Tacticals and PVS Strategies: A Small Step Semantics - Kirchner, Floren|
The need for a small step semantics and more generally for a thorough documentation and understanding of Coq's tacticals and PVS's strategies arise with their growing use and the progressive uncovering of their subtleties. The purpose of the following study is to provide a simple and clear formal framework to describe their detailed semantics, and highlight their differences and similarities.
Keywords: NEURAL NETS; DESIGN OPTIMIZATION; SUBSTRUCTURES; SENSITIVITY ANALYSIS; ALGORITHMS; ITERATION
|Preparing for the human factors/ergonomics job market - Shapiro, Ronald G.|
The panel is designed to help an individual decide on a specialization in human factors/ergonomics and to prepare to enter the human factors job market. Panelists were selected to represent a cross-section of the field, and are from the following sectors: the electronics industry (Megan Brown), loss prevention research (Max Fogleman), academia (Joe Goldberg), the computer industry (Dick Granda), the government (Joe Hale), and consulting (Liz Sanders).
Keywords: MULTIDISCIPLINARY DESIGN OPTIMIZATION; MATHEMATICAL MODELS; ACTIVE CONTROL; OPTIMIZATION; SENSITIVITY; SURVEYS
|Investigation of an Experimental Supersonic Axial-Flow Compressor - Erwin, John R.|
An investigation is in progress at the Langley Laboratory of the NACA to explore the possibilities of axial-flow compressors operating with supersonic velocities relative to the blade rows. The first phase of this investigation, a study of supersonic diffusers, has been reported. The second phase, an analysis of supersonic compressors, has also been reported. Preliminary calculations have shown that very high pressure ratios across a stage, together with somewhat increased mass flows, are possib...
Keywords: MULTIDISCIPLINARY DESIGN OPTIMIZATION; AUTONOMY; ALGORITHMS; SIMULATION; FORMAT; REUSE
|Hypervelocity Aeroheating Measurements in Wake of Mars Mission Entry Vehicle - Hollis, Brian R.|
Detailed measurements of aerodynamic heating rates in the wake of a Mars-Pathfinder configuration model have been made. Heating data were obtained in a conventional wind tunnel, the NASA LaRC 31'' Mach 10 Air Tunnel, and in a high-enthalpy impulse facility, the NASA HYPULSE expansion tube, in which air and CO2 were employed as test gases. The enthalpy levels were 0.7 MJ/kg in the Mach 10 Tunnel, 12 MJ/kg at Mach 9.8 for HYPULSE CO2 tests and 14 MJ/kg at Mach 7.9 for HYPULSE air tests...
Keywords: MULTIDISCIPLINARY DESIGN OPTIMIZATION; DESIGN ANALYSIS; NONLINEARITY; QUADRATIC EQUATIONS
|Elements of Designing for Cost - Dean, Edwin B.|
During recent history in the United States, government systems development has been performance driven. As a result, systems within a class have experienced exponentially increasing cost over time in fixed year dollars. Moreover, little emphasis has been placed on reducing cost. This paper defines designing for cost and presents several tools which, if used in the engineering process, offer the promise of reducing cost...
Keywords: MULTIDISCIPLINARY DESIGN OPTIMIZATION; AUTONOMY; LANGUAGES; GRAPH THEORY; DECISION MAKING
|MIT 22.033 Nuclear Systems Design Project, Fall 2011|
In this capstone design project course, students design a nuclear reactor that generates electricity, hydrogen and biofuels. Lectures introduce each major subsystem and explore design methods, and are followed by mid-term and final student presentations. View the complete course: http://ocw.mit.edu/22-033F11 Instructor: Dr. Michael Short License: Creative Commons BY-NC-SA More information at http://ocw.mit.edu/terms
Keywords: nuclear energy; reactor design; design optimization; biofuel; carbon sequestration
|Laser Induced Aluminum Surface Breakdown Model - Chen, Yen-Sen|
Laser powered propulsion systems involve complex fluid dynamics, thermodynamics and radiative transfer processes. Based on an unstructured grid., pressure-based computational aerothermodynamics, platform, several sub-nio'''dels describing such underlying physics as laser ray tracing and focusing, thermal non-equilibrium, plasma radiation and air spark ignition have been developed. This proposed work shall extend the numerical platform and existing sub-models to include the aluminum wall surface ...
Keywords: MULTIDISCIPLINARY DESIGN OPTIMIZATION; APPROXIMATION; ALGORITHMS; LOADS (FORCES); TRUSSES; BEAMS (SUPPORTS); DESIGN OPTIMIZATION; DISPLACEMENT; WEIGHT REDUCTION; CONFERENCES; POLYNOMIALS; DEGREES OF FREEDOM
|Modeling of the EUV and X-Ray Emission Spectra Induced by the Solar Winds Ions in the Heliosphere - Kharchenko, Vasil|
We have carried out investigation of the EUV and X-ray emission spectra induced in interaction between the Solar Wind (SW) and interstellar neutral gas. The spectra of most important SW ions have been computed for the charge-exchange mechanism of X-ray emission using new accurate spectroscopic data from recent laboratory measurements and theoretical calculations. Total spectra have been constructed as a sum of spectra induced in the charge-exchange collisions by individual O(exp q), C(exp q), N(...
Keywords: COMPUTATIONAL FLUID DYNAMICS; AERODYNAMICS; SENSITIVITY; ITERATIVE SOLUTION; DERIVATION; DESIGN OPTIMIZATION; ELECTRONIC EQUIPMENT
|The problem with multiple robots - Huber, Marcus J.|
The issues that can arise in research associated with multiple, robotic agents are discussed. Two particular multi-robot projects are presented as examples. This paper was written in the hope that it might ease the transition from single to multiple robot research.
Keywords: ALGORITHMS; CONVERGENCE; NONLINEAR EQUATIONS; NONLINEAR PROGRAMMING; NONLINEAR SYSTEMS; OPTIMIZATION; DESIGN ANALYSIS; MULTIDISCIPLINARY DESIGN OPTIMIZATION; NONLINEARITY
|Automatic Weather Station (AWS) Lidar - Rall, Jonathan A. R.|
A ground based, autonomous, low power atmospheric lidar instrument is being developed at NASA Goddard Space Flight Center. We report on the design and anticipated performance of the proposed instrument and show data from two prototype lidar instruments previously deployed to Antarctica.
Keywords: DYNAMIC LOADS; MULTIDISCIPLINARY DESIGN OPTIMIZATION; SUPERSONIC TRANSPORTS; CIVIL AVIATION; ALGORITHMS; STABILITY; MASSIVELY PARALLEL PROCESSORS; AIRCRAFT DESIGN
|Excitation of Coupled Slotline Mode in Finite Ground CPW with Unequal Ground Plane Widths - Ponchak, George E.|
The coupling between the desired CPW mode and the unwanted coupled slotline mode is presented for finite ground coplanar waveguides with unequal ground plane widths. Measurements, quasi-static conformal mapping, and Finite-Difference Time-Domain analysis are performed to determine the dependence of the slotline mode excitation on the physical dimensions of the FGC line and on the frequency range of operation...
Keywords: ARCHITECTURE (COMPUTERS); APPLICATIONS PROGRAMS (COMPUTERS); MULTIDISCIPLINARY DESIGN OPTIMIZATION; SYSTEMS ENGINEERING; ITERATION; ORGANIZATIONS; CONTROL THEORY; VECTORS (MATHEMATICS)
|Geomagnetic Activity Indicates Large Amplitude for Sunspot Cycle 24 - Hathaway, D. H.|
The level of geomagnetic activity near the time of solar activity minimum has been shown to be a reliable indicator for the amplitude of the following solar activity maximum. The geomagnetic activity index aa can be split into two components: one associated with solar flares, prominence eruptions, and coronal mass ejections which follows the solar activity cycle and a second component associated with recurrent high speed solar wind streams which is out of phase with the solar activity cycle...
Keywords: DESIGN OPTIMIZATION; SENSITIVITY; STRUCTURAL DESIGN; DISPLACEMENT; DESIGN ANALYSIS; CENTRAL PROCESSING UNITS; OPTIMIZATION; PRECISION
|A Pseudo-Temporal Multi-Grid Relaxation Scheme for Solving the Parabolized Navier-Stokes Equations - White, J. A.|
A multi-grid, flux-difference-split, finite-volume code, VULCAN, is presented for solving the elliptic and parabolized form of the equations governing three-dimensional, turbulent, calorically perfect and non-equilibrium chemically reacting flows. The space marching algorithms developed to improve convergence rate and or reduce computational cost are emphasized. The algorithms presented are extensions to the class of implicit pseudo-time iterative, upwind space-marching schemes...
Keywords: DESIGN ANALYSIS; SHAPE OPTIMIZATION; MULTIDISCIPLINARY DESIGN OPTIMIZATION; AERODYNAMIC CONFIGURATIONS; FINITE ELEMENT METHOD; PARALLEL PROCESSING (COMPUTERS)
|A High-Fidelity Batch Simulation Environment for Integrated Batch and Piloted Air Combat Simulation Analysis - Goodrich, Kenneth H.|
A batch air combat simulation environment known as the Tactical Maneuvering Simulator (TMS) is presented. The TMS serves as a tool for developing and evaluating tactical maneuvering logics. The environment can also be used to evaluate the tactical implications of perturbations to aircraft performance or supporting systems. The TMS is capable of simulating air combat between any number of engagement participants, with practical limits imposed by computer memory and processing power...
Keywords: APPROXIMATION; SYSTEMS ENGINEERING; SYSTEMS INTEGRATION; MULTIDISCIPLINARY DESIGN OPTIMIZATION; MATHEMATICAL MODELS; POLYNOMIALS; KRIGING
|The Chesapeake Lighthouse and Aircraft Measurements for Satellites (CLAMS) Experiment - Smith, William L., Jr.|
NASA has developed an Earth Observing System (EOS) consisting of a series of satellites designed to study global change from space. The EOS flagship is the EOS TERRA satellite, launched in December 1999, equipped with five unique sensors to monitor and study the Earth s heat budget and many of the key controlling variables governing the Earth's climate system. CLAMS, the Chesapeake Lighthouse and Aircraft Measurements for Satellites field campaign was conducted from NASA Wallops Flight Facility ...
Keywords: AUTOMATA THEORY; COMPUTER PROGRAMS; DESIGN OPTIMIZATION; FAULT TOLERANCE; STATISTICAL ANALYSIS; PARSING ALGORITHMS; MANUFACTURING
|Dot Projection Photogrammetric Technique for Shape Measurements of Aerospace Test Articles - Jones, Thomas W.|
Results from initial laboratory investigations with the dot projection photogrammetric technique are presented for three wind-tunnel test articles with a range of surface scattering and reflection properties. These test articles are a semispan model and a micro air vehicle with a latex wing that are both diffusely reflecting, and a highly polished specularly reflecting model used for high Reynolds number testing...
Keywords: FORCE DISTRIBUTION; STRUCTURAL DESIGN; DESIGN OPTIMIZATION; EXPERIMENT DESIGN; COMPUTERIZED SIMULATION; FINITE ELEMENT METHOD; DYNAMIC RESPONSE
|Single Axis Piezoceramic Gimbal - Horner, Garnett|
This paper describes the fabrication, testing, and analysis of a single axis piezoceramic gimbal. The fabrication process consists of pre-stressing a piezoceramic wafer using a high-temperature thermoplastic polyimide and a metal foil. The differential thermal expansion between the ceramic and metal induces a curvature. The pre-stressed, curved piezoceramic is mounted on a support mechanism and a mirror is attached to the piezoceramic...
Keywords: AIRCRAFT STRUCTURES; AIRCRAFT DESIGN; STRUCTURAL DESIGN; COMPOSITE MATERIALS; DESIGN ANALYSIS; AEROELASTICITY; SLENDER WINGS; DESIGN OPTIMIZATION
|Exploratory Calibration of Adjustable-Protrusion Surface-Obstacle (APSO) Skin Friction Vector Gage - Hakkinen, Raimo J.|
The design of an adjustable-protrusion surface-obstacle (APSO) skin friction vector gage is presented. Results from exploratory calibrations conducted in laminar and turbulent boundary layers at the Washington University Low-Speed Wind Tunnel and for turbulent boundary layers at speeds up to Mach 2 on the ceiling of the NASA Glenn Research Center 8- X 6-ft Supersonic Wind Tunnel are also discussed...
Keywords: CONTROL SYSTEMS DESIGN; DESIGN OPTIMIZATION; MICROGRAVITY; VIBRATION ISOLATORS; CONTROLLERS; INTERNATIONAL SPACE STATION; SPACEBORNE EXPERIMENTS; ACTUATORS; MAGNETS
|A Patched-Grid Algorithm for Complex Configurations Directed Towards the F/A-18 Aircraft - Thomas, James L.|
A patched-grid algorithm for the analysis of complex configurations with an implicit, upwind-biased Navier-Stokes solver is presented. Results from both a spatial-flux and a time-flux conservation approach to patching across zonal boundaries are presented. A generalized coordinate transformation with a biquadratic geometric element is used at the zonal interface in order to treat highly stretched viscous grids and arbitrarily-shaped zonal boundaries...
Keywords: DESIGN OPTIMIZATION; DESIGN ANALYSIS; KNOWLEDGE BASED SYSTEMS; ARTIFICIAL INTELLIGENCE; DECISION SUPPORT SYSTEMS
|Complex Volume Grid Generation Through the Use of Grid Reusability - Alter, Stephen J|
This paper presents a set of surface and volume grid generation techniques which reuse existing surface and volume grids. These methods use combinations of data manipulations to reduce grid generation time, improve grid characteristics, and increase the capabilities of existing domain discretization software. The manipulation techniques utilize physical and computational domains to produce basis function on which to operate and modify grid character and smooth grids using Trans-Finite Interpolat...
Keywords: ALGORITHMS; NONLINEAR PROGRAMMING; MULTIDISCIPLINARY DESIGN OPTIMIZATION; APPROXIMATION; ACCURACY; NONLINEARITY; MATHEMATICAL MODELS
|Serrated-Planform Lifting-Surfaces - NON|
A novel set of serrated-planform lifting surfaces produce unexpectedly high lift coefficients at moderate to high angles-of-attack. Each serration, or tooth, is designed to shed a vortex. The interaction of the vortices greatly enhances the lifting capability over an extremely large operating range. Variations of the invention use serrated-planform lifting surfaces in planes different than that of a primary lifting surface...
Keywords: COMPUTER SYSTEMS DESIGN; MULTIDISCIPLINARY DESIGN OPTIMIZATION; COMPUTER AIDED DESIGN; AIRCRAFT DESIGN; DESIGN ANALYSIS; AEROSPACE VEHICLES
|Recent Cycle Time Reduction at Langley Research Center - Kegelman, Jerome T|
The NASA Langley Research Center (LaRC) has been engaged in an effort to reduce wind tunnel test cycle time in support of Agency goals and to satisfy the wind tunnel testing needs of the commercial and military aerospace communities. LaRC has established the Wind Tunnel Enterprise (WTE), with goals of reducing wind tunnel test cycle time by an order of magnitude by 2002, and by two orders of magnitude by 2010...
Keywords: SPACE COMMUNICATION; DESIGN OPTIMIZATION; MANNED SPACE FLIGHT; EARTH OBSERVATIONS (FROM SPACE)
|Large-Eddy Simulation of Laminar-Turbulent Transition in a Swept-Wing Boundary Layer - Huai, X.|
A continuous adjoint approach for obtaining sensitivity derivatives on unstructured grids is developed and analyzed. The derivation of the costate equations is presented, and a second-order accurate discretization method is described. The relationship between the continuous formulation and a discrete formulation is explored for inviscid, as well as for viscous flow. Several limitations in a strict adherence to the continuous approach are uncovered, and an approach that circumvents these difficul...
Keywords: MULTIDISCIPLINARY DESIGN OPTIMIZATION; MODELS; BODY-WING CONFIGURATIONS; LAUNCH VEHICLES; BAYES THEOREM; APPROXIMATION
|The Effect of Symbology Location and Format on Attentional Deployment within a Cockpit Display of Traffic Information - Johnson, Walter W.|
The present experiment employed target detection tasks to investigate attentional deployment during visual search for target aircraft symbols on a cockpit display of traffic information (CDTI). Targets were defined by either a geometric property (aircraft on a collision course with Ownship) or a textual property (aircraft with associated altitude tags indicating an even altitude level). Effects of target location and target brightness (highlighting) were examined...
Keywords: DESIGN OPTIMIZATION; DECISION MAKING; STOCHASTIC PROCESSES; TECHNOLOGY TRANSFER; SYSTEMS ENGINEERING; SELECTION; AEROSPACE SYSTEMS
|Exhaust Gas Modeling Effects on Hypersonic Powered Simulation at Mach 10 - Tatum, Kenneth E.|
A numerical study was performed to investigate the accuracy and validity of cold-gas simulation of actual hot scramjet exhaust within a Mach 10 free stream over a representative single-stage-to-orbit airbreathing configuration. In particular, exhausts of various noncombusting chemistry models were studied to characterize their effects on the vehicle aftbody performance and the plume flow field definition...
Keywords: AIRCRAFT DESIGN; COMPUTER AIDED DESIGN; MULTIDISCIPLINARY DESIGN OPTIMIZATION; PARAMETERIZATION; COMPUTATIONAL GRIDS
|Trajectory Design Strategies for the NGST L2 Libration Point Mission - Folta, David|
The Origins' Next Generation Space Telescope (NGST) trajectory design is addressed in light of improved methods for attaining constrained orbit parameters and their control at the exterior collinear libration point, L2. The use of a dynamical systems approach, state-space equations for initial libration orbit control, and optimization to achieve constrained orbit parameters are emphasized. The NGST trajectory design encompasses a direct transfer and orbit maintenance under a constant acceleratio...
Keywords: DESIGN ANALYSIS; NONLINEAR PROGRAMMING; DESIGN OPTIMIZATION; NORMAL DENSITY FUNCTIONS; GENETIC ALGORITHMS
|A 3-D CFD Analysis of the Space Shuttle RSRM With Propellant Fins 1 sec. Burn-Back - Morstadt, Robert A|
In this study 3-D Computational Fluid Dynamic (CFD) runs have been made for the Space Shuttle RSRM using 2 different grids and 4 different turbulent models, which were the Standard KE, the RNG KE, the Realizable KE, and the Reynolds stress model. The RSRM forward segment consists of 11 fins. By taking advantage of the forward fin symmetry only half of one fin along the axis had to be used in making the grid...
Keywords: AERODYNAMICS; DESIGN OPTIMIZATION; TECHNOLOGY ASSESSMENT; AIRCRAFT DESIGN; AIRCRAFT INDUSTRY; AIRLINE OPERATIONS; AERONAUTICAL ENGINEERING
|The EOS Aqua/Aura Experience: Lessons Learned on Design, Integration, and Test of Earth-Observing Satellites - Nosek, Thomas P|
NASA and NOAA earth observing satellite programs are flying a number of sophisticated scientific instruments which collect data on many phenomena and parameters of the earth's environment. The NASA Earth Observing System (EOS) Program originated the EOS Common Bus approach, which featured two spacecraft (Aqua and Aura) of virtually identical design but with completely different instruments. Significant savings were obtained by the Common Bus approach and these lessons learned are presented as in...
Keywords: CREEP PROPERTIES; MATERIALS SELECTION; POLYETHYLENES; METEOROLOGICAL BALLOONS; CONSTITUTIVE EQUATIONS; STRUCTURAL DESIGN; DESIGN OPTIMIZATION; VISCOELASTICITY; BALLOON FLIGHT
|Proceedings of the Space Station Freedom Clinical Experts Seminar - NON|
These are the proceedings of the Space Station Freedom Health Maintenance Facility 1990 Clinical Experts Seminar held August 27-29, 1990, at the Nassau Bay Hilton, Houston, Texas. Contained within are the agenda, list of medical consultants, executive summary, individual presentations, and the comments generated from the working groups. Issues include the adequacy of current Health Maintenance Facility for Space Station Freedom; impact of having, or not having, an ACRV or physician on board Spac...
Keywords: TURBINE BLADES; GAS TURBINES; AIR COOLING; LIQUID COOLING; COATINGS; BLADE TIPS; HEAT TRANSFER; DESIGN OPTIMIZATION
|Preliminary Results of the GPS Flight Experiment on the High Earth Orbit AMSAT-OSCAR 40 Spacecraft - Moreau, Michael C.|
The GPS flight experiment on the High Earth Orbit (HEO) AMSAT-OSCAR 40 (AO-40) spacecraft was activated for a period of approximately six weeks between 25 September and 2 November, 2001, and the initial results have exciting implications for using GPS as a low-cost orbit determination sensor for future HEO missions. AO-40, an amateur radio satellite launched November 16, 2000, is currently in a low inclination, 1000 by 58,800 km altitude orbit...
Keywords: USER REQUIREMENTS; DESIGN OPTIMIZATION; SPACECRAFT INSTRUMENTS; ARCHITECTURE (COMPUTERS); TEST FACILITIES; SENSORS; DEVELOPMENT
|The Livingstone Model of a Main Propulsion System - Bajwa, Anupa|
Livingstone is a discrete, propositional logic-based inference engine that has been used for diagnosis of physical systems. We present a component-based model of a Main Propulsion System (MPS) and say how it is used with Livingstone (L2) in order to implement a diagnostic system for integrated vehicle health management (IVHM) for the Propulsion IVHM Technology Experiment (PITEX). We start by discussing the process of conceptualizing such a model...
Keywords: AERODYNAMICS; COMPUTATIONAL FLUID DYNAMICS; COMPRESSORS; COMPUTER AIDED DESIGN; DESIGN OPTIMIZATION; COMPRESSING; THREE DIMENSIONAL MODELS
|SRB Altitude Switch Assembly Wire Harness Failure - Blanche, Ji|
This paper presents an assessment of two wire harness failures that had occurred in Solid Rocket Booster Altitude Switch Assemblies S/N 200001 and S/N 20002. A list of modifications to EDU #4 and modification of qualification units 2000001 and 2000002 are also presented.
Keywords: ROBOTS; TEAMS; INSPECTION; APPLICATIONS PROGRAMS (COMPUTERS); DESIGN OPTIMIZATION; SIMULATION; ORBITAL ASSEMBLY; TUBES; LIQUID PROPELLANT ROCKET ENGINES
|Formal Methods for Life-Critical Software - Butler, Ricky W.|
The use of computer software in life-critical applications, such as for civil air transports, demands the use of rigorous formal mathematical verification procedures. This paper demonstrates how to apply formal methods to the development and verification of software by leading the reader step-by-step through requirements analysis, design, implementation, and verification of an electronic phone book application...
Keywords: DESIGN TO COST; COST ANALYSIS; COMPLEXITY; DESIGN OPTIMIZATION; AEROSPACE INDUSTRY; COST ESTIMATES; COST REDUCTION
|Environmental Geographic Information Systems (EGIS) at Stennis Space Center (SSC) - Carr, Hugh|
This viewgraph presentation includes: 1) Background of SSC Environmental GIS (EGIS); 2) Principal Center Activities; 3) SSC's GIS Applications: a) Environmental Emergency Response Tool, b) CERCLA, c) Facilities Master Planning, d) Natural Resource Management and Site Assessment.
Keywords: AEROSPACE INDUSTRY; COMPETITION; PRODUCT DEVELOPMENT; COSTS; TAGUCHI METHODS; TOTAL QUALITY MANAGEMENT; MULTIDISCIPLINARY DESIGN OPTIMIZATION
|Dual Mode Shock-Expansion/Reflected-Shock Tunnel - Erdos, John I.|
NASA s HYPULSE facility at GASL has been reconfigured to permit free jet testing of the Hyper-X flowpath at flight Mach numbers of 7 and 10. Among the required changes are addition of a converging-diverging nozzle to permit operation in a reflected shock tunnel mode, a 7 ft. diameter test cabin and a 30 in. diameter contoured nozzle. However, none of these changes were allowed to interfere with rapid recovery of the prior shock-expansion tunnel mode of operation, and indeed certain changes shoul...
Keywords: KRIGING; DESIGN ANALYSIS; MODELS; MULTIDISCIPLINARY DESIGN OPTIMIZATION; COMPUTATIONAL FLUID DYNAMICS; ERROR ANALYSIS; FINITE ELEMENT METHOD; POLYNOMIALS
|The 1999 NASA Aerospace Battery Workshop - NON|
This document contains the proceedings of the 32nd annual NASA Aerospace Battery Workshop, hosted by the Marshall Space Flight Center on November 16-18, 1999. The workshop was attended by scientists and engineers from various agencies of the US Government, aerospace contractors, and battery manufacturers, as well as international participation in like kind from a number of countries around the world...
Keywords: NONLINEAR PROGRAMMING; ANALYTIC FUNCTIONS; MULTIDISCIPLINARY DESIGN OPTIMIZATION; HISTORIES; FORMULATIONS; DECOMPOSITION; ALGORITHMS; AUTONOMY
|A Novel Four-Node Quadrilateral Smoothing Element for Stress Enhancement and Error Estimation - Tessler, A.|
A four-node, quadrilateral smoothing element is developed based upon a penalized-discrete-least-squares variational formulation. The smoothing methodology recovers C1-continuous stresses, thus enabling effective a posteriori error estimation and automatic adaptive mesh refinement. The element formulation is originated with a five-node macro-element configuration consisting of four triangular anisoparametric smoothing elements in a cross-diagonal pattern...
Keywords: DESIGN ANALYSIS; FLUID DYNAMICS; MULTIDISCIPLINARY RESEARCH; MULTIDISCIPLINARY DESIGN OPTIMIZATION; SYSTEMS ENGINEERING; COMPLEX SYSTEMS; AERODYNAMIC CONFIGURATIONS
|Performance of the Star Tracker Lightshades on the Earth Observing Satellite (EOS) Aqua - Kenny, Thomas|
The TRW built EOS Aqua spacecraft uses two Ball Aerospace CT-602 star trackers to provide attitude updates to the 3-axis, zero momentum, controller. Two months prior to the scheduled launch of Aqua, Ball reported an error in the design of the star tracker lightshades. The lightshades, which had been designed specifically for the EOS Common spacecraft, were not expected to meet the stray light rejection requirements of the mission, thus impacting the overall spacecraft pointing performance...
Keywords: LIFE (DURABILITY); NICKEL HYDROGEN BATTERIES; ELECTRIC CHARGE; DESIGN OPTIMIZATION; DYNAMIC MODELS; CUMULATIVE DAMAGE; CALCULUS; NONLINEARITY
|Motion-Based System Identification and Fault Detection and Isolation Technologies for Thruster Controlled Spacecraft - Wilson, Edward|
By analyzing the motions of a thruster-controlled spacecraft, it is possible to provide on-line (1) thruster fault detection and isolation (FDI), and (2) vehicle mass- and thruster-property identification (ID). Technologies developed recently at NASA Ames have significantly improved the speed and accuracy of these ID and FDI capabilities, making them feasible for application to a broad class of spacecraft...
Keywords: DESIGN OPTIMIZATION; FLUIDICS; MASS FLOW; JET FLOW; VIABILITY; DESIGN ANALYSIS; COMPRESSED AIR
|High-Speed Load Distribution of the Wing of a 3/16-Scale Model of the Douglas XSB2D-1 Airplane with Flaps Deflected - Barnes, Robert H|
The tests reported herein were made for the purpose of determining the high-speed load distribution on the wing of a 3/16 scale model of the Douglas XSB2D-1 airplane. Comparisons are made between the root bending moment and section torsional moment coefficients as obtained experimentally and derived analytically. The results show good correlation for the bending moment coefficients but considerable disagreement for the torsional moment coefficients, the measured moments being greater than the an...
Keywords: SPACE STATION FREEDOM; SPACECRAFT DESIGN; SPACE STATION STRUCTURES; SPACE STATION MODULES; INTERNATIONAL COOPERATION; MISSION PLANNING; ORBITAL ASSEMBLY; DESIGN OPTIMIZATION; SCHEDULES
|High-Altitude Observations of the Polar Wind - Moore, T. E.|
Plasma outflows, escaping from Earth through the high-altitude polar caps into the tail of the magnetosphere, have been observed with a xenon plasma source instrument to reduce the floating potential of the POLAR spacecraft. The largest component of H() flow, along the local magnetic field (30 to 60 kilometers per second), is faster than predicted by theory. The flows contain more O() than predicted by theories of thermal polar wind, but also have elevated ion temperatures...
Keywords: MULTIDISCIPLINARY DESIGN OPTIMIZATION; SYSTEMS ENGINEERING; MATHEMATICS; FLUID MECHANICS; TURBULENCE; FLOW CHARACTERISTICS; LATTICES (MATHEMATICS); INFORMATION THEORY; COMPUTER TECHNIQUES; SYSTEMS ANALYSIS
|Bio-Optical Measurement and Modeling of the California Current and Polar Oceans - Mitchell, B. Gre|
The principal goals of our research are to validate standard or experimental products through detailed bio-optical and biogeochemical measurements, and to combine ocean optical observations with advanced radiative transfer modeling to contribute to satellite vicarious radiometric calibration and advanced algorithm development. To achieve our goals requires continued efforts to execute complex field programs globally, as well as development of advanced ocean optical measurement protocols...
Keywords: MULTIDISCIPLINARY DESIGN OPTIMIZATION; CRASHWORTHINESS; PARALLEL COMPUTERS; PARALLEL PROCESSING (COMPUTERS); AUTOMOBILES; CRASHES; SIMULATION; COMPUTER SYSTEMS PERFORMANCE; COMPUTER TECHNIQUES
|The NASA Goddard Space Flight Center Virtual Science Fair - Bolognese, Jeff|
This report describes the development of the NASA Goddard Space Flight Center Virtual Science Fair, including its history and outgrowth from the traditional regional science fairs supported by NASA. The results of the 1999 Virtual Science Fair pilot program, the mechanics of running the 2000 Virtual Science Fair and its results, and comments and suggestions for future Virtual Science Fairs are provided...
Keywords: MASSIVELY PARALLEL PROCESSORS; PARALLEL PROCESSING (COMPUTERS); SYSTEMS ANALYSIS; MULTIDISCIPLINARY DESIGN OPTIMIZATION; MULTIDISCIPLINARY RESEARCH; STRUCTURAL ANALYSIS; FLOW CHARACTERISTICS; SUPERCOMPUTERS; MODULARITY
|Locations of Bromide Ions in Tetragonal Lysozyme Crystals - Lim, Kap|
Anions have been shown to play a dominant role in the crystallization of chicken egg-white lysozyme from salt solutions. Previous studies employing X-ray crystallography have found one chloride ion binding site in the tetragonal crystal form of the protein and four nitrate ion binding sites in the monoclinic form. In this study the anion positions in the tetragonal form were determined from the difference Fourier map obtained from lysozyme crystals grown in bromide and chloride solutions...
Keywords: MULTIDISCIPLINARY DESIGN OPTIMIZATION; STUDENTS; OPTIMIZATION; MECHANICAL ENGINEERING; SYSTEMS ENGINEERING; AEROSPACE SYSTEMS; DESIGN ANALYSIS; INFORMATION MANAGEMENT; INFORMATION TRANSFER; COORDINATION; COSTS; TRADEOFFS
|Hoop Tensile Characterization Of SiC/SiC Cylinders Fabricated From 2D Fabric - Verrilli, Michael J.|
Tensile stress-strain properties in the hoop direction were obtained for 100-mm diameter SiC/SiC cylinders using ring specimens machined from the cylinder ends. The cylinders were fabricated from 2D balanced fabric with several material variants, including wall thickness (6, 8, and 12 plies), Sic fiber type (Sylramic, Sylramic-iBN, Hi-Nicalon, and Hi-Nicalon S), fiber sizing type, and matrix type (full CVI Sic, and partial CVI plus melt-infiltrated SiC-Si)...
Keywords: LARGE SPACE STRUCTURES; INFLATABLE SPACE STRUCTURES; TOWERS; DESIGN OPTIMIZATION; SYNTHETIC FIBERS; HIGH ALTITUDE; THIN FILMS; ENGINES; SAFETY
|Development of Temperature Sensitive Paints for the Detection of Small Temperature Differences - Oglesby, Donald M.|
Temperature sensitive paints (TSP s) have recently been used to detect small temperature differences on aerodynamic model surfaces. These types of applications impose stringent performance requirements on a paint system. The TSP s must operate over a broad temperature range, must be physically robust (cannot chip or peel), must be polishable to at least the smoothness of the model surface, and must have sufficient sensitivity to detect small temperature differences...
Keywords: AEROSPIKE ENGINES; ENGINE DESIGN; MULTIDISCIPLINARY DESIGN OPTIMIZATION; ROCKET NOZZLES; STRUCTURAL ANALYSIS; THREE DIMENSIONAL MODELS; COMPUTATIONAL FLUID DYNAMICS; NONLINEARITY; STRUCTURAL DESIGN
|Chemical Fingerprinting Program for RSRM Critical Materials - McClennen, William H.|
This viewgraph presentation provides information on the chemical fingerprinting of RSRM (Reusable Sold Rocket Motor) components. A chemical fingerprint can be used to identify a material, to differentiate it from similar looking materials, or lead to its source. It can also identify unexpected changes to a vendor or supplier's material, and monitor aging.
Keywords: GENETIC ALGORITHMS; NEURAL NETS; DESIGN OPTIMIZATION; ROBOTS; INSPECTION; SPACE SHUTTLE MAIN ENGINE; CADMIUM SULFIDES; ROBOT SENSORS; SCIENTIFIC VISUALIZATION; SIMULATION
|Occurrence and Forms of Water and Ice on the Earth and Beyond, and the Origin(s) of Life - Blake, David F|
The natural history of the biogenic elements (H,C,O,N) from their first association within cold molecular clouds to their delivery to the Earth during the late bombardment of the inner solar system, is intimately linked to water ice. The earliest organic compounds are formed in cold interstellar molecular clouds as a result of UV and thermal processing of sub-micrometer ice grains which contain trapped carbon and nitrogen molecules...
Keywords: MULTIDISCIPLINARY DESIGN OPTIMIZATION; ACCURACY; MATHEMATICAL MODELS; NUMERICAL ANALYSIS; LINEAR EQUATIONS; SURVEYS; NAVIER-STOKES EQUATION; FINITE ELEMENT METHOD
|An Acoustic Charge Transport Imager for High Definition Television Applications: Reliability Modeling and Parametric Yield Prediction of GaAs Multiple Quantum Well Avalanche Photodiodes - Hunt, W. D.|
Reliability modeling and parametric yield prediction of GaAs/AlGaAs multiple quantum well (MQW) avalanche photodiodes (APDs), which are of interest as an ultra-low noise image capture mechanism for high definition systems, have been investigated. First, the effect of various doping methods on the reliability of GaAs/AlGaAs multiple quantum well (MQW) avalanche photodiode (APD) structures fabricated by molecular beam epitaxy is investigated...
Keywords: PARALLEL PROGRAMMING; PROGRAMMING LANGUAGES; MULTIDISCIPLINARY DESIGN OPTIMIZATION; DESIGN ANALYSIS; COMPILERS; CLIMATE MODELS; FLUID FLOW; AIRCRAFT DESIGN; AIRCRAFT MODELS
|Numerical Simulation of Wake Vortices Measured During the Idaho Falls and Memphis Field Programs - Proctor, Fred H|
A numerical large-eddy simulation model is under modification and testing for application to aircraft wake vortices. The model, having a meteorological framework, permits the interaction of wake vortices with environments characterized by crosswind shear, stratification, and humidity. As part of the validation process, model results are compared with measured field data from the 1990 Idaho Falls and the 1994-1995 Memphis field experiments...
Keywords: EXPERIMENTATION; DATA ACQUISITION; INTEGRATED CIRCUITS; CONTROLLERS; DESIGN OPTIMIZATION; LINE OF SIGHT; LARGE SPACE STRUCTURES; FLEXIBLE BODIES; FABRICATION